MVNO comparison
T-Mobile Legacy Migration: QCI Impact & MVNO Exit Paths
Technical guide mapping the QCI priority drop when moving from legacy T-Mobile postpaid to MVNOs, with worked bill calculations for lost promos and a decision matrix for Mint, Metro, Google Fi, and US Mobile exits as of August 2026.
- Updated
- 2026-08-27
- Reading time
- 11 min
TL;DR
T-Mobile legacy plan migration keeps most Magenta holdouts on inferred QCI 6 smartphone priority—but porting to Mint, Metro, or US Mobile Light Speed drops you to QCI 7 on the same towers. Google Fi Unlimited Plus is the main wholesale exit that preserves QCI 6 inference. Worked bill math shows promo translation failures can cost $150–250/mo before you even consider the MVNO trade-off.
- As of August 27, 2026, legacy Magenta and Experience targets both map to inferred QCI 6 on smartphone traffic; MVNO exits on T-Mobile host drop to QCI 7.
- Our August 2026 exit-path matrix scores five MVNO routes against QCI preservation, four-line bill restoration, hotspot headroom, and port friction.
- Worked examples model a KickBack household and a six-free-line promo failure using list prices from The Mobile Report's July 2026 migration sheet.
- Fix promo billing errors before porting—T-Mobile pledged free-line restoration July 28, 2026 per Ars Technica; leaving early forfeits backdated credits.
- For arena commuters who need queue position, Google Fi Unlimited Plus beats Mint on priority; for Wi-Fi-heavy households, Mint restores pre-migration pricing.
T-Mobile legacy plan migration in August 2026 forces millions of Simple Choice, ONE, and Magenta subscribers onto Experience rate plans—and the decision that follows is not whether your towers change, but whether you accept repricing or exit to an MVNO and absorb a QCI priority drop from inferred QCI 6 (postpaid smartphone traffic) to QCI 7 (Mint, Metro, US Mobile Light Speed). Staying on Experience preserves queue position on congested cells; porting to a budget MVNO restores pre-migration pricing on the same T-Mobile map at the cost of one scheduling tier. Google Fi Unlimited Plus is the exception: it often keeps QCI 6 inference while replacing separate roaming add-ons many legacy families already buy.
Stat: On 3GPP non-GBR bearers, QCI 6 carries priority level 6 (300 ms delay budget) versus QCI 7 at level 7 (100 ms)—the lower integer wins the scheduler when a sector is saturated. Source: ETSI TS 123.203, accessed August 27, 2026.
Original research: MVNO exit-path matrix (August 2026)
We compiled the table below on August 27, 2026 from published plan pages, QCI inference from our June 2026 congestion test, and four-line total-bill modeling against Experience Signature Family list math. Each exit path scores 1 (poor fit) to 5 (best fit) on four goals legacy migrants name in support threads: QCI preservation, bill restoration, hotspot headroom, and port simplicity.
| Exit path | Host | Inferred phone QCI | 4-line bill model (Aug 2026) | Hotspot (high-speed) | QCI score | Bill score | Hotspot score | Port score | Total (/20) |
|---|---|---|---|---|---|---|---|---|---|
| Stay on Experience Signature | T-Mobile | 6 | $184–216/mo list (autopay) | 60 GB | 5 | 2 | 5 | 5 | 17 |
| Google Fi Unlimited Plus | T-Mobile (+ others) | 6 | ~$260/mo ($65/line) | 100 GB pooled | 5 | 2 | 4 | 4 | 15 |
| Mint Mobile Unlimited (12-mo prepaid) | T-Mobile | 7 | ~$128/mo ($32/line equiv.) | 20 GB | 2 | 5 | 2 | 4 | 13 |
| Metro Unlimited BYOD | T-Mobile | 7 | ~$160/mo ($40/line) | 20 GB | 2 | 4 | 2 | 5 | 13 |
| US Mobile Light Speed | T-Mobile | 7 | ~$100/mo ($25/line, 30 GB tier) | 20 GB | 2 | 5 | 2 | 3 | 12 |
| Visible+ (host change) | Verizon | 8 (inference) | ~$150/mo ($37.50/line) | 75 GB | 3 | 4 | 4 | 3 | 14 |
Methodology: Dollar figures exclude taxes, device payments, and account-specific promos. QCI columns tagged (inference)—carriers do not print QCI on bills. Bill scores favor exits that land below $140/mo for four lines, a threshold we derived from August 2026 Reddit and Ars comment threads where restored Experience bills cluster.
Dataset (Schema.org): name T-Mobile legacy migration MVNO exit-path scoring matrix — QCI & bill restoration; datePublished 2026-08-27; license CC BY 4.0; URL fragment #exit-path-matrix.
What QCI changes when you leave legacy postpaid
QoS Class Identifier (QCI) is a 3GPP scheduling label—lower integers usually win airtime when a sector is congested. T-Mobile does not mail you a QCI number; independent analyses (Coverage Critic, BroadbandMap, updated June 17, 2026) place Magenta, Experience More, and Experience Beyond smartphone traffic in QCI 6, alongside Google Fi and most T-Mobile-branded postpaid.
The legacy migration itself is mostly a QCI wash for smartphone traffic: you are not losing priority by accepting Experience—you are losing grandfathered SOC pricing and sometimes promo stacks that took years to assemble. The QCI drop happens only when you port out to bulk MVNO lanes.
| Traffic type | Legacy Magenta (typical) | Experience Signature (post-migration) | Mint / Metro / US Mobile Light Speed |
|---|---|---|---|
| Smartphone data | QCI 6 (inference) | QCI 6 (inference) | QCI 7 (inference) |
| Hotspot / tether | QCI 8 (inference) | QCI 8 (inference) | QCI 8 (inference) |
| Congestion lever | Premium postpaid queue | Same premium queue | MVNO bulk queue + Mint 50 GB heavy-user policy |
| When gap matters | Stadium exits, rush hour | Same | Noticeable vs postpaid on contested cells |
T-Mobile's Open Internet FAQ (checked August 27, 2026) confirms a second axis: on-device data is prioritized above tethering when resources compete. That means your new 60 GB Signature hotspot bucket is high-speed in marketing terms, but Friday 6 PM laptop tethering can still feel slower than phone-native traffic—even before you consider an MVNO exit.
"We prioritize on-device data (except that of significant data users, as described above) over tethering data at times and at locations where there are competing customer demands for network resources, which may result in slower tethering speeds."
Where I am less sure: whether every Experience Signature Select variant inherits identical QoS marking on day one, or whether SOC-code rollout lags create a two-week window of mixed behavior. Anecdotally, mass billing migrations sometimes precede network policy pushes—run your own congestion A/B off-peak versus 5:30 PM before filing an FCC complaint.
For a deeper QCI primer, see what is QCI and our Google Fi vs Mint priority test.
Worked bill calculations: when promos fail to translate
Methodology (August 27, 2026): We modeled two household profiles using The Mobile Report's July migration spreadsheet list prices, cross-checked against Ars Technica's July 28 reporting. Figures exclude taxes, device payments, and account-specific Insider discounts—your account will differ.
Worked example — Elena, Austin nurse practitioner (KickBack household)
Elena holds four voice lines on Magenta with KickBack credits on two lines ($10/line back when usage stays under 2 GB). Pre-migration list math:
| Line | Legacy Magenta list | KickBack credit (2 lines) | Net pre-migration |
|---|---|---|---|
| Line 1 (primary) | $40 | — | $40 |
| Line 2 | $30 | −$10 | $20 |
| Line 3 | $30 | −$10 | $20 |
| Line 4 | $30 | — | $30 |
| Monthly subtotal | $130 | −$20 | $110 |
Post-migration Experience Signature Family (B) with $6/line base hike and KickBack not carried forward on Experience targets (per July 2026 migration mapping):
| Line | Experience Signature list | Lost KickBack | Net post-migration |
|---|---|---|---|
| Line 1 | $46 | — | $46 |
| Line 2 | $36 | +$10 vs legacy net | $36 |
| Line 3 | $36 | +$10 vs legacy net | $36 |
| Line 4 | $36 | — | $36 |
| Monthly subtotal | $154 | — | $154 |
Elena's migration cost: +$44/mo from list hikes and lost KickBack—not the headline $24 ($6 × 4) alone. If Elena ports four lines to Mint Unlimited at $32/line 12-month prepaid equivalent ($128/mo), she saves $26/mo versus restored Experience but drops to QCI 7. Her commute through IH-35 at 5 PM is congested; Elena should stay on Experience unless she tests Mint on a secondary line first.
Worked example — Marcus, Phoenix warehouse supervisor (free-line promo failure)
Marcus's account—pattern documented in Ars Technica's July 28, 2026 report—had three paid lines and six free lines for about $50/mo pre-migration. Post-migration Experience Signature with promo translation failure:
| Item | Pre-migration | Post-migration (promo failed) | Delta |
|---|---|---|---|
| Paid lines (3) | ~$50 total (promo stack) | $46 × 3 = $138 | +$88 |
| Free lines (6) | $0 | $36 × 6 = $216 | +$216 |
| Monthly subtotal | ~$50 | ~$354 | +$304 |
T-Mobile's July 28 statement pledged backdated free-line restoration for affected accounts. Marcus should not port until credits post—porting trades a fixable $304 spike for QCI 7 on nine lines and re-port friction across devices.
If Marcus's promos restore to ~$80/mo (three paid + fees), MVNO math changes:
| Exit path | 9-line bill model | vs restored ~$80 T-Mobile | QCI |
|---|---|---|---|
| Stay on Experience (promos fixed) | ~$80 | baseline | 6 |
| Mint Unlimited (12-mo prepaid) | ~$288 ($32 × 9) | +$208 | 7 |
| Google Fi Unlimited Plus | ~$585 ($65 × 9) | +$505 | 6 |
Taken position for Marcus: Stay and fight for promo restoration. MVNO exits do not beat a $80 restored postpaid bill on nine lines—regardless of QCI.
MVNO exit paths: steel-manning each route
The case for staying on Experience
The strongest advocate for staying argues you keep T-Mobile-native QCI 6 smartphone priority—often a full tier above Mint or Metro (QCI 7 inference per our congestion test). You gain 60 GB of marketed high-speed hotspot on Signature, unlimited premium on-phone data without legacy 480p optimization, and a five-year price lock T-Mobile is actively selling. For Priya, a Chicago litigation paralegal who uploads depositions from Union Station at rush hour, the migration is a congestion win on smartphone uploads even after $6/line.
Rebuttal: Staying only wins when your restored bill is tolerable. Promo translation failures turn rational retention into hostage-taking—fix billing before evaluating QCI. If restored pricing exceeds ~$35/line, the QCI 6 premium may not justify $150+/mo over Mint for a Wi-Fi-heavy household.
The case for Mint or Metro
Mint's advocate points to $32/line 12-month prepaid equivalent ($128/mo for four lines, checked August 27, 2026) on the same T-Mobile towers—restoring pre-migration economics for Elena-type households. Metro adds retail support and slightly better congested-cell stability in our June 2026 matrix. Neither brand publishes QCI; field inference consistently maps both to QCI 7.
Rebuttal: You are trading one scheduling tier for savings that evaporate if you commute through capacity cliffs. Mint's 50 GB heavy-user policy (updated October 28, 2025) adds a second queue on unlimited plans during congestion. Test your worst cell before porting the whole family.
The case for Google Fi Unlimited Plus
Fi Plus preserves QCI 6 inference while bundling international data many legacy families buy separately—rational for James, a Denver sales engineer who hits Canada twice monthly and already pays $15–40 in roaming add-ons. At $65/line, four-line Fi math (~$260/mo) beats restored Experience plus roaming for heavy travelers.
Rebuttal: Fi Plus costs more than Mint for domestic-only users. If James works from home on fiber, $132/mo in Fi premium over Mint is paying for queue position he never uses.
Decision flow: which exit path fits your migration profile
- Audit your restored Experience bill — download pre- and post-migration PDFs; flag missing free-line credits, phantom hotspot add-ons (~$15/mo), and KickBack losses.
- If promos failed, escalate before porting — cite T-Mobile's July 28, 2026 Ars statement; demand SOC-level restoration, not a 12-month goodwill credit. See forced migrations QCI & promo impact.
- If restored bill < ~$35/line and you hit congested cells → stay on Experience.
- If restored bill > ~$35/line and usage is Wi-Fi-heavy → Mint or US Mobile Light Speed (accept QCI 7).
- If you need QCI 6 plus international → Google Fi Unlimited Plus.
- If Verizon coverage beats T-Mobile in your ZIP → compare Visible+ instead of T-Mobile MVNOs.
Run a congestion baseline on your worst cell before porting: same location, 5:15–6:30 PM weekday window, speed test plus a 30-second video call. Pair with how to check QCI level if your Android build exposes bearer hints.
Verdict
T-Mobile legacy plan migration splits into two questions shoppers conflate: "Did my priority change?" (usually no for Magenta → Experience smartphone traffic) and "Did my total bill change?" (almost always yes). MVNO exit paths change the first answer to yes—you drop from QCI 6 to QCI 7 on Mint, Metro, and US Mobile Light Speed unless you pay Google Fi Unlimited Plus rates.
For Elena with a +$44/mo KickBack loss on four lines, staying on Experience is rational if IH-35 congestion is daily reality. For Marcus with nine lines and a $304 promo failure, fix billing before any port—the MVNO math does not beat a restored $80 postpaid bill.
My position as of August 27, 2026: Port to Mint when your restored Experience bill clears ~$140/mo for four lines and your phone usage is mostly on Wi-Fi. Pay for Fi Unlimited Plus when you need QCI 6 and international bundles in one bill. Do not port in anger on the first migration notice—model promo restoration first, then accept the QCI trade knowingly.
For broader MVNO comparisons, see T-Mobile legacy migration MVNO alternatives, July 2026 escape routes, and best T-Mobile MVNOs.
FAQ
Short answers; details are in the article above.
- If you accept Experience Signature, More, or Beyond, smartphone data generally stays at inferred QCI 6—the same bucket most Magenta lines occupied before migration. The QCI change happens when you port to Mint, Metro, or US Mobile Light Speed, which typically drop to QCI 7 on identical T-Mobile towers. Google Fi Unlimited Plus is the main wholesale MVNO exit that preserves QCI 6 inference.
- The base migration hike is up to $6 per line on list pricing. Promo translation failures—vanished free lines, lost KickBack credits, or Insider discounts that do not map to Experience SOC codes—can add $150–250/mo on four-to-nine-line households before taxes. T-Mobile admitted July 28, 2026 that some free-line discounts failed to apply and pledged backdated restoration.
- Google Fi Unlimited Plus ($65/line as of August 27, 2026) is the primary T-Mobile-hosted MVNO that field evidence maps to QCI 6. Mint Mobile, Metro by T-Mobile, and US Mobile Light Speed sit at QCI 7 inference—one scheduling step lower during congestion. Fi costs more but may replace separate international roaming add-ons postpaid migrants already pay for.
- No. Resolve promo restoration first. T-Mobile's July 28, 2026 statement to Ars Technica commits to backdated free-line credits on affected accounts. Porting while credits are pending risks leaving money on the table and trading QCI 6 for QCI 7 before you know your true post-migration cost baseline.
- On lightly loaded suburban and rural sectors, QCI 6 and QCI 7 phones often speed-test within measurement noise. The gap explodes at stadium exits, rush-hour downtown cores, and holiday retail corridors—exactly where legacy Magenta subscribers who stayed for priority feel the downgrade after porting to Mint or Metro.
- Stay if your restored bill is under ~$35/line and you commute through congested cells. Port to Mint when restored pricing exceeds ~$140/mo for four lines and your usage is Wi-Fi-heavy. Choose Fi Unlimited Plus when you need QCI 6 plus international bundles. The right exit depends on whether migration hurt your wallet or your queue position—and for most Magenta holdouts, it is the wallet.