The FCC today announced new rules that will require all carriers as well as OTT messaging apps to support text-to-911.

In a push to make the service more uniformly available, the new rules expand availability beyond the U.S.’s big four carriers, all of which agreed to support the service by May 2014. Now all other carriers will have to make the service available and “interconnected” text messaging providers including OTT apps like Whatsapp.

The order calls for smaller carriers and messaging apps to have the service in place by the end of the year. After that, if a 911 call center requested the service, those entities will have six months to deploy.

The FCC said text-to-911 is already up and running in 611 call centers serving parts of 16 states along with all of Maine and Vermont. Under FCC regulations, areas without support for the service are required to send an immediate bounce-back message to people attempting to reach 911 via text.

CTIA issued a critical response to the FCC’s new mandate, saying the wireless industry is voluntarily implementing the technology and that efforts to “codify” the agreement could produce adverse responses.

“The chilling effect of the Commission’s proposed enforcement role is particularly worrisome in situations where, as here, the voluntary agreement involves new services that face challenging obstacles to implementation,” CTIA wrote in a post.

Commissioner Ajit Pai also expressed concerns with the new rules. He said the amount of support at call centers is still too small to properly support the service and that pushing it into all carrier as well as popular messaging apps might make the public overly confident in the fledgling service.

FCC Chairman Tom Wheeler said that while voice calls will still be the best option for contacting 911, text-to-911 provides an alternative for individuals who for varying reasons can’t call.

CCA CEO Steven Berry shared Wheeler’s enthusiasm for expanding text-to-911 but reserved some skepticism about call center technology keeping up and opening the network gates to OTT apps.

“While we remain concerned about the speed of public safety answering points’ (PSAPs) technology adoption and OTT providers’ access to our carrier members’ networks, CCA is pleased the FCC acknowledges the need for certainty before implementing these new requirements,” Berry said in a statement.