Delta SkyMiles has been more focused than just about any airline on making their frequent flyer program revenue based, on both the earning and redemption side. They were the first of the big three US airlines to introduce revenue based mileage earning, and they’re also the only airline to let those with their co-branded credit card redeem miles for a penny each towards the cost of a ticket.
They’ve been using that one cent per mile valuation pretty aggressively as they’ve expanded the options for redeeming SkyMiles, and it looks like that has been expanded even further now. You can now redeem Delta SkyMiles to cover all kinds of fees (ticket change fees, award ticket redeposit fees, same-day confirmed fees, etc.), as well as upgrade costs (be it to a preferred seat, Comfort+, first class, or Delta One).
Per the SkyMiles News & Updates page:
Starting June 20th, 2017, SkyMiles Members can use their miles instead of money for even more products and services when calling Delta Reservations, giving Members more flexibility and options than ever before.
Members can now use their miles for:
- Upgrading to Delta Comfort+®, First Class or Delta One®
- Selecting Preferred Seats
- Ticket change fees
- Award Ticket redeposit fees (waived for Diamond and Platinum Medallion Members as part of their Medallion Benefits)
- Same-Day Confirmed fees (waived for Diamond, Platinum and Gold Medallion Members as part of their Medallion Benefits)
- External ticket charge (applies to all tickets issued in the United States or Canada by someone other than Delta)
To take advantage of these options, contact Delta Reservations at 1-800-323-2323.
Learn more about the many ways Members can use their miles.
Mileage amounts for upgrading to Delta Comfort+, First Class or Delta One are limited to the first $1,000 in fees. All mileage redemptions are nonrefundable. Upgrading to Delta Comfort+, First Class or Delta One, and using the Same-Day Confirmed option, are subject to availability and all product terms. Additional terms may apply.

You can now redeem your SkyMiles towards the cost of cash upgrades
While the amounts aren’t published, I would imagine that Delta will give you about a penny per mile towards the cost of any of the above. As of now this functionality is only available by phone, though hopefully it’s implemented online at some point as well.
Perhaps this isn’t the most glamorous way to use your SkyMiles, though I do appreciate the number of options Delta has for redeeming their miles. SkyMiles might not be the most valuable mileage currency, but unlike other programs, there’s actually a “floor” value to their miles, since you can redeem them quite easily across the board for at least a penny each, which isn’t bad. American and United don’t have that level of flexibility, so while you can get outsized value with those currencies, others may not even be able to get a penny of value per point.
(Tip of the hat to @IadisGr8)
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