Amazon expands same-day delivery in Baltimore, Dallas, Indianapolis, NYC, Philadelphia, DC

Amazon is expanding its same-day delivery service in six of the 12 cities where it is offered, its latest push to get shoppers to sign up for its $99 Prime loyalty program.

Amazon will introduce a $5.99 same-day delivery fee for an unlimited number of products for Prime members in Baltimore, Dallas, Indianapolis, New York City, Philadelphia and Washington. Previously, the fee was $3.99 per item.

It will also offer a "Get it Today" filter on its site where customers can filter results by whether they are available for same-day delivery or not. The cutoff time is now noon. Previously, it had ranged from 7:30 a.m. to 11 a.m., depending on the city.

These services had been available since May in Los Angeles, Phoenix, San Francisco and Seattle.

Seattle-based Amazon has been trying to beef up services for its Prime loyalty program that includes free two-day shipping on many items. It has added a grocery delivery service and offered music streaming, original TV shows and apps and a set-top video streaming box. It also expanded Sunday deliveries.

About a million items, including movies, games, home products and back-to-school supplies, are available for same-day delivery.

For people without Prime, the same-day delivery fee remains $9.98 for the first item and 99 cents for each additional item.